Asbestos is used as a reinforcing fibre in fibre-filled plastic materials. Two important properties of the resulting composite material are the impact strength and the flexural strength. When most types of chrysotile asbestos are used as reinforcing fibres, the composite material has generally relatively good flexural strength and stiffness but poor impact strength. In many instances, it is therefore advantageous to improve the impact strength.
Some naturally occurring, very harsh chrysotile asbestos fibre having particularly good flexural strength and stiffness properties as a reinforcing fibre in fibre-filled resins is known to be relatively long, very straight and smooth-surfaced. Available quantities of this fibre are limited and a comparable asbestos fibre has not heretofore been produced synthetically.